This application is for the continuation of the "Multidisciplinary Training in Cancer Research" program at Vanderbilt University (VU) initiated almost 20 years ago by Harold L. Moses. In this renewal application, the current P.I., Lynn M. Matrisian, proposes to change the name to "Microenvironmental Influences in Cancer" to reflect the enhanced focus of program faculty on the cellular and molecular biology underlying tumorhost interactions. The purpose of this training program is to prepare pre- and post-doctoral trainees for a career in basic and translational cancer research. The program supports predoctoral training of 6 Ph.D. or M.D./Ph.D. candidates and postdoctoral training of 3 Ph.D. or M.D. candidates/year. The Microenvironmental Influences in Cancer Training Program (MICTP) takes place in the backdrop of an active and growing Medical Center with state-of-the-art facilities, a vibrant NCIdesignated comprehensive cancer center, a basic science Department of Cancer Biology, an Interdisciplinary Graduate Program in Biomedical Sciences, an active Office of Postdoctoral Affairs, an effective Alliance with the neighboring minority-serving Meharry Medical College (MMC), and Graduate Programs in Cancer Biology at both VU and MMC. There is a comprehensive course in Cancer Biology, courses focusing on the tumor microenvironment, and abundant opportunities for extended learning and interactions through ongoing seminar series, retreats, and research-in-progress presentations. The postdoctoral training program consists primarily of laboratory research under the guidance of a faculty supervisor. The 27 preceptors include faculty from the VU departments of Cancer Biology, Cell &Dev. Biology, Pathology, Radiation Oncology, Surgery, and Medicine, and the Cancer Biology division of the Department of Biomedical Sciences at MMC. Although the emphasis is on basic and translational research, a special feature of this training grant is the requirement for exposure to clinical cancer research and care through rotations through medical and surgical clinics and tumor boards. This training program has been highly effective in selecting and advancing the careers of motivated and productive trainees in the field of cancer research.